Polyoxymethylene dimethyl ethers, also referred to as Poly(dimethoxymethane), can be synthesized to present properties compatible with those of conventional diesel fuel. It has the chemical structure of CH3—O—(CH2—O)n—CH3. Poly(dimethoxymethane) with n=1 is dimethoxymethane (DMM), which although it has attractive properties for fuels applications, when n ranges from 3 to 5 the poly(dimethoxymethane) can be blended directly into diesel with no need for engine modifications. Furthermore, because there are no carbon-carbon bonds in the poly(dimethoxymethane) molecule, the fuel burns clean without the generation of soot.
Poly(dimethoxymethane) can be synthesized from methanol and formaldehyde as depicted from the following equation:CH3OH+nCH2O↔CH3O(CH2O)nCH2 CH3O(CH2O)2CH2+nCH2O↔CH3O(CH2O)2+nCH2 For initial dimethoxymethane synthesis or further production of poly(dimethoxymethane), it is necessary to understand the dynamics of formaldehyde in solution. Formaldehyde readily reacts with water and methanol to produce methylene glycol (HOCH2OH, MG), poly(oxymethylene) glycols (H(OCH2)nOH, MGn, n>1), hemiformal (HOCH2OCH3, HF), and poly(oxymethylene) hemiformals (H(OCH2)nOCH3, HFn, n>1). The model presented for poly(dimethoxymethane) production takes into consideration the equilibrium conditions for formaldehyde and its availability for the dimethoxymethane synthesis reaction. Although processes for forming poly(dimethoxymethane) are known, the costs of synthesis can be unreasonably high thereby inhibiting its application in products such as diesel fuel.
Accordingly, there is a need for improved methods and systems for producing poly(dimethoxymethane).